The United Nations appealed Tuesday to the air transport industry to help fly food in urgently to the Horn of Africa, where millions of people are starving due to a severe drought.

"We're making an appeal to the air transport industry for free and heavily discounted cargo space to help us transport emergency nutrition supplies to the Horn of Africa," said Marixie Mercado, spokeswoman for the UN children's agency.

British Airways, Lufthansa, Virgin Atlantic and UPS have all offered to transport between 15 and 50 metric tonnes a week, but UNICEF is "looking to others to step forward as well."

The agency is trying to get 5,000 metric tonnes of food from its warehouses in Europe to the region, but it costs about $350,000 (250,000 euros) to transport just 100 metric tonnes of food by cargo jumbo jet from France to Nairobi.

"That costs us pretty much the cost of the cargo itself," noted Mercado.

While transportation by sea is another option, there is a six-week gap and not all who are in need can afford to wait, said the UNICEF spokeswoman.

"There are over 2.3 million acutely malnourished children in the Horn of Africa. More than half a million will die if they don't get help within weeks," said Mercado.

"We are asking the air transport industry for free or heavily discounted cargo space to transport this therapeutic food to children who will die without it," she stressed.

The UN declared a famine in two regions in Somalia in July, and estimated that over 12 million people across the Horn of Africa region are in dire need of help.